The invention set forth in this specification pertains to both a new and improved method and a new and improved apparatus for manufacturing stress-skin panels.
Such panels normally consist of two so-called "skins" such as flat sheets or substantially flat sheets of aluminum or another material separated by and bonded to a so-called core which is normally of a comparatively rigid, cellular character. Frequently such cores have consisted of rigid, porous polymer compositions such as cellular polystyrene, porous polyurethane and the like, although on many occasions such cores have also been of a number of different types. Although such stress-skin panels have been manufactured in many different ways it is considered that most conventionally they have been manufactured by conventional laminating techniques serving to laminate the two skins of such a panel on opposite sides of the core of such a panel.
Although such laminating techniques are unquestionably utilitarian it is not considered that they are as inexpensive as desired in connection with the manufacture of stress-skin panels. Also it is considered that such laminating techniques are disadvantageous for use in manufacturing stress-skin panels because normally side edges of the panels produced using these techniques are not especially shaped as as to be capable of being directly interlocked with the side edges of other panels in forming a joint such as is used in connection with various types of building applications. The cost of shaping such side edges so that they can be used in forming such joints is undesirably expensive. Further, on occasion it is considered that such laminating techniques are disadvantageous as not providing stress-skin panels in which the skins are satisfactorily and uniformly bonded to the cores of such panels.
As a result of the recognition of such factors a number of efforts have been made at providing stress-skin panels constructed using other techniques than laminating techniques as briefly indicated in the preceding discussion. It is not considered that an understanding of the present invention requires a detailed discussion of such alternate manufacturing techniques. Although such alternate techniques can be considered desirable in some respects, they are also considered entirely undesirable in others for a wide variety of different reasons.
Among such reasons are problems in producing stress-skin panels having substantially uniform characteristics between their sides and having adequately uniform dimensions in which the skins of such panels are effectively bonded to the cores of such panels. In connection with both of these matters it is noted that a stress-skin panel should employ a core having substantially uniform physical properties between its sides if it is to be acceptable in many applications.